Fluid coupling



June 13, 1944.

G. R. `Flsluurqsolu FLUID COUPLING Filed May 13, 1940 2 Sheets-Sheetl INVENTOR. 62114)); RPQ/Zilli! 9&7017.

ATTORNEYS- G. R. PENNINGTON 2,351,286 l June 13, 944.

v l FLUID coUPLING Filed May 13, 1940 2 sheets-sheet 2v INVENToR @afn i 31071752702!! 5 ATToRNEYa Patented June 13, 1944 FLUID CoUrLING Gordon R. Pennington, {Bloomiield Hills, Mich..

assignor to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Application May 13, V1940, SerialNo. 334,755

1 Claim. (Cl. 60-54) This invention relates to uid couplings of the kinetic type.

An object Yof the invention is the provision of a coupling of the foregoing type which is highly elcient in the transmission of driving torque horsepower under average cruising conditions but which will operate with a relatively low drag when in stalled condition. In carrying out theabove I preferably employ a coupling wherein the chamber in which the working fluid circulates is bounded by substantially smooth flowing lines and wherein the relatively low drag or high slip at stall conditions is brought about by partially unloading this chamber. This unloading action is accomplished by so arranging and proportioning the fluid working chamber as to provide a reservoir within the normal contines of the coupling into which the working fluid is evacuated from. the working chamber under high slip conditions without the aid of scoops or other similar means, at the same time maintaining the axial and radial dimensions of the coupling at a minimum. A coupling having the foregoing characteristics is particularly adapted for use in the drive of motor vehicles wherein it is highly desirable to have little or no drag when the vehicle vaned structures are so positioned and so contoured as to develop relatively -high eillciency in torque transmission for a relatively smal1 area of working surface, and which will facilitatev evacuation of the fluid from the working chamber therefor, without the use of baiiies, scoops or the like, to eiiect relatively low drag when high slippage occurs between the impeller and runner structures. y

Another object of the invention is to provide a coupling fabricated from a plurality of sheet metal stampings, preferably welded together.

Other objects and advantages of the invention will be more apparent from the following description taken in connection with the accompanying drawings, in which:

Fig. 1 is a sectional elevational view of a hydraulic coupling embodying the invention. A

Fig. 2 is a side elevational view of the inner sideA of the impeller structure shown in Fig. 1.

Fig. 3 is aside elevational view of the inner side of a portion of the impeller structure prior is at rest, with the prime mover therefor operating, in order to prevent creep of the vehicle.

Another object of the invention is the provision of a coupling having the foregoing characteristics which is free from bulges and abnormal contours in accommodating the fluid working chamber and an evacuating reservoir, the working chamber being confined to the radially outer region of i the coupling and the reservoir arranged at the radially inner region thereof, the relative capacities of the working chamber and reservoir being such that a substantial portion of the fluid content of the chamber can be evacuated there-v from into the reservoir` when the coupling is in stalled condition.

A still further object of the. invention is the provision, in `a coupling of the foregoing type, of improved means for supporting the vaned parts thereof, more particularly the vaned part of the impeller structure, so positioned that atleast a portion of such supporting means not only provides a wall delimiting a portion of the iiuid working chamber but also provides a .wall directly separatingV the latter from the reservoir into which fluid is evacuated under high 'slip conditions.

'A still further object of the invention is t0 provide a hydraulic coupling working chamber forming impeller and runner wherein the -iluidto assembly as shown in Figs. .1 and 2.

Fig. i is a sectional view taken on lineat of Fig. 3.

Fig. 5 is a fragmentary sectional elevational view similar to Fig. 1 but showing a modified form of thefinvention.

The invention is illustrated and described in connection with a fluid coupling ofthe kinetic type having a toroid circuit for the working liquid formed' by juxtaposed annular vaned impeller and runner structures, dished in cross-section and opening one toward the other. While the improved coupling is particularly adapted for esta'blishing a drive between a driving part In, such as the crankshaft of an internal combustion en gine, and a driven part ii, it will be understood that couplings embodying the invention may be l utilized in drives other thanthose for motor vehicles.

The coupling includes an annular casing I2,

preferably of sheet metal and having spaced separately formed -walls I3 and I6 having the edge portions thereof welded together as'indicated at I5, with anannular band It bridging the edge portions for preventing loose welding flash from gaining access to the interior ofthe easing. When employed as herein contemplated. the coupling functions asa flywheel structure and is provided with aring gear l l. a portion of the wall I3 being formed to provide an external seat i8 for the gear I1 and a resultant pocket I9 interiorly of the casing.A A plurality of cooling ns 20 are with the shaft part of the casing thus suitably secured to the casing I2 for radiating heat therefrom.

The casing side walls I3 and I4 have openings 2l and 22 respectively, providing a central coupling opening through which extends a hub forming sleeve 23 splined to the driven part II, the latter beingadapted to be releasably connected A sealing unit, generally indicated at 24, cooperates with the hub for sealing the opening 22. The unit 24 includes a -ring 25 mounted on the hub or sleeve 23 rotation relative thereto and having opposed side II' journaled in the sleeve 23.l

Aradially extending in a manner to accomodate sealing ribs 2l, one in sealing engagement with the adjacent abutment of the hub 23. and the other in sealing engagement with a ring 23 encircling the hub. A Sylphon bellows has one end secured to the ring 2B and the opposite-end thereto to a ring 3|) threaded in the wall bounding the opening 22 of the casing wall I4. A coil spring 3|, acting between an annular abutment 32 retained in spring loading position by the ring 30 and the ring 28.y urges the latter into friction sealing engagement with the adjacent sealing rib 25 of the ring 25 and the other rib 28 into similar engagement with the .abutment 21. The ring 25 has sufficient clearance with the sleeve 23 lto accommodate itself to irregularities or eccentricities resulting from manufacture or assembly. A gasket .33 is interposed between a radial dange of the ring and the outer surface of the wall I4.

The casing I2 is drivingly secured to the driving part III by means of a centrally apertured annulus 34 secured as by welding to the casing wall I3 and is secured by a plurality of bolts 35 to a flange of the driving part I0. The sleeve 23 is suitably journaled in the annulus by a bearing unit 36, the right hand end faces, as viewed in Fig. 1 of the races thereof abutting respectively -the annulus 34 and sleeve 23. A retainer 31 ex.-

tends between the races preventing-passage of metal particles into the ball races andthe wall I3 extends over the openings in the annulus 34 accommodating the bolts 35 and has an vaxially terminal dange 33 abutting the radially inner part of the annulus and welded thereto.'

Bositioned within the casing are impeller and runner structures cooperating to` form. a duid 5I) welded to the retainer 41.

asanaec numeral 33. included an annular dished sheet metal retainer 43 opening toward the side wall I3 of the casing and having circumferentially spaced, radially extending vanes 4I each provided with suitable tabs which are welded to the retainer 40 as more specifically hereinafter set forth in connection with the impeller structure. The retainer 40 includes an annular attaching flange 42 extending inwardly from the vaned part for attachment as by welding to an annular flange 43of the sleeve 23. The flange 42 is reinforced by an annular plate 44 secured thereto by welding, the dange 42 and plate 44 having registering openings 45 therein.

The impeller structure generally indicated by the numeral 46, includes an annular dished sheet metal vane retainer 41l which is seated in the dished part of the radially outer portion of the casing wall` I3 and driving secured thereto as by weldingY as indicated at 48 in Figs. 1 and 2, the welding being at alternately radially spaced locations as indicated in Fig. 2. A plurality of passage formng vcircumferentially spaced, radially extending vanes 4S are provided each having tabs The retainer 41 and vanes 48 are first brought to the assembly shown in Figs. 3 and 4 and this assembly is then secured to the casing wall I3 to provide the structure shown in Fig. I.

The structures 33 and 43 cooperate to provide a chamber, indicated at 5I, for the circulation of the duid working medium, the chamber being located in the radially outer portion of the couvvane retainer 40 to accommodate the dow of duid from the reservoir.52 radially outwardly and thence into the working chamber 5I. The impeller vane lretainer l1 has the major portion thereof abutting the casing Wall I3 and thus coworking chamber forthe circulation'of the workving duid, these structures being so located that the chamber is condned to the radially outer the working 'chamber by evacuating the duid therefrom to `the' reservoir and to impede the immediate and direct return thereof to the work- -ing chamber, thereby minimizing-.the torque transmitted from the impeller to the runner when it is desired that the vehicle, for example. remain at rest with the prime mover operating.l

The duid working chamber is formed by juxtaposed, dished impeller and runner structures each including circumferentially tending vanes `providing duid passages. The runner structure generally indicated by the providing a reservoir operates therewith to bound the major portion of that part of the chamber 5I formed by the impeller structure. the retainer 41 masking the pocket indicated at I3. 'I'he radially inner .por-

l tion 53 of the retaineil 41 projects from the side wall I3 toward and terminates adjacent the runner structure, thus supporting the radially inner ends of the vanes 43 1in axially spaced relation to the wall I3 and thereby avoiding the'necessity for imparting to the wall that contour. which would otherwise be necessary where the radially inner ends of the vanes are secured directlyto the wall: This arrangement also has the ad vantage of permitting the wall portion to be properly contoured to facilitate attachment thereof to the driving member Il.l The radially inner portion 53 of the'retainer 41de1imits a portion of the duid working chamber independently of the adjacent casing side wall, this vane retainer por--A spaced, radially ex-4 t tion overlying the reservoir 52 and impeding di- "rect passage of duid therefrom to the chamber 5I.

During the normal operation of the coupling as when the engine is driving the car the duid in the impeller structure is -thrown radially outward under the induence of centrifugal force set up L.; rotation'- and is rotated about the; axis of rotation ofthe coupling. The arcuate contour of the duid passages of the impeller structure directs the fluid to the runner structure to transmit its rotation to the latter. When'the impeller and runner structures are turning at different speeds, the fluid is circulated by the differential centrifugal force between the two structures and therefore due to the contour of the fluid passages of the vaned structures, about an axis transverse with respect to the axis about which the couplingv rotates. When the impeller and runner structures operate at relatively low slip the latter circulation is at a relatively low velocity. When the impeller and runner structures operate at relatively high slip,.it being understood that one hundred percent slip between these structures represents a stalled condition of the runner structure at which time the latter is completely restrained against rotation, fluid is circulated around the said transverse axis at a relatively.

high velocity. v

The said circulation of fluid around the trans'- verse axis develops a. centrifugal force in the particles of fluid with respect to that axis. At the outer diameter of the casing .this centrifugal force adds to that developed as a result of rotation around the main longitudinal axis ofl the coupling. However, at the inner diameter of the working chamberthe centrifugal force with respect to the transverse axis opposes that existing with respect to the main longitudinal axis. Consequently, underl relatively high slip conditions and relatively low coupling speeds the centrifugal force withrespect to the transverse axis becomes greater than that with respect to the longitudinal axis at the region 54 and the liquid at the.

radialy inner portion of the chamber moves out of the working chamber into the reservoir 52.

When the conditions of operation are so altered that the speed of the coupling is relatively increased or the slip is relatively decreased, a condition is reached in whichthe centrifugal force at the region 54 around the transverse axis will be less than thev centrifugal force around the longitudinal axis and the force of the latterewill prevail and the liquid will return to the chamber I. The fiow of :fluid at the region 5I as afore- -said is in addition to the normal fluid ow at the region 55.

The portion 53 of the impeller vane retainer 4l which overlies the chamber 52 prevents the too rapid return of the iuid into the working chamber 5I as a result of rotation of the impeller structure when the balance of the centrifugal forces is causing the liquid to move radially outwardly at the region or gap 5I.

To increase to the practical maximum the volume of the chamber 52, the radially inner portion of the impeller and runner vaned structures ad'- jacent the region 54 have a contour substantially flat in cross-section, this contoured portion directly overlying the reservoir 52. I'he flat contour does not impair emciency of the' -cou'- tri pling for transmission of driving torque at low slip because it conforms. approximately to the natural path of flow of the liquid in this region.

under low slip operating conditions when the centrifugal force relative to the main or longitudinal axisis greater than the centrifugal force relative to the transverse axis. The contour of the bounding wall at the region 55 and adjacent thereto represents in cross-section a continuous radius of curvature for facilitating the desired Y circulation of fluid in this region.

In the Fig. 5 embodiment of the invention, the

' coupling and parts thereof are generally similar t0 the ShOWing in Fig. 1 and like parts have been identified by like numerals. However, in this form. of the invention the radially outer portion of the impeller vane retainer 41' terminates short of and does'not mask the pocket I9. vThe tab at the radially-.outer end of each vane is secured preferably by welding directly to the casing wall I3.

Although but several specific embodiments of j the invention have herein been shown and de- .external surface thereof and a registering internal pocket, a ring gear on said seat, an annular dish-shaped sheet metal vane carrying member received in said wall dish-shaped portion and drivingly secured thereto, said member extending across said pocket, and a hub-like member for drivingly securing the casing to a coupling driving means having an attaching face abutting the external surface of said dish-shaped wall portion at a point intermediate said seat and the axis of rotation of the casing and welded thereto, said hub-like member having a, central journalling opening therein and an attachment-receiving body intermediate its' attaching face and central opening provided with spaced attachment receiving openings, said wall overlapping said perforated body in spaced relation thereto and having the edge portion at said opening deflected generally longitudinally with respect to said axis. the end face of said deflected edge portion abutting said hub-like member in uid tight relation therewith, and attaching studs respectively threaded into said attachment receiving openings and removable therefrom when the hub-like member is welded to said casing wall as aforesaid.

GORDON R. PENNINGTON. 

